Classroom lesson · Wildlife · 🇲🇩 Moldova

Eurasian Beaver

The river engineer that builds dams with felled trees

Photo · Wikimedia Commons

What is it?

The Eurasian beaver is the largest rodent in Europe and one of the most impressive animal engineers in the world. Beavers use their enormous front teeth to cut down trees, then use the wood to build dams across streams and rivers. The dam creates a deep, still pond where the beaver builds a cosy home called a lodge.

Tell me more

A beaver's front teeth are orange-coloured because they contain iron, which makes them extra hard and strong. The teeth grow continuously throughout the beaver's life — which is useful, because gnawing through tree trunks wears them down constantly. A beaver can cut through a small tree in just a few minutes, leaving behind a pointed stump that looks like a sharpened pencil.

The dam a beaver builds is a remarkable feat of engineering. The beaver packs sticks, branches, mud and stones together to create a barrier across the stream. Water backs up behind the dam to form a pond. The pond has to be deep enough not to freeze solid in winter — the beaver stores food underwater and needs to be able to swim under the ice to reach it.

In the middle of the pond stands the lodge — a dome of sticks and mud with an underwater entrance. From the outside it looks like a pile of branches. Inside, above the waterline, there is a dry, warm chamber where the family sleeps and the young kits grow up. Because the entrance is underwater, no fox or wolf can simply walk in.

Eurasian beavers almost disappeared from Moldova in the past because they were hunted for their thick fur. Conservationists worked hard to bring them back by releasing beavers into suitable rivers and protecting them. Now they are found along several of Moldova's rivers and in the Codru forest area. A beaver pond also benefits many other animals — frogs, dragonflies, herons and otters all use the habitat beavers create.

In the classroom

Walk your class through this in 15 minutes.

Talk together

Discussion prompts

  1. 01How does building a dam help a beaver survive winter? Think about food, shelter and safety.
  2. 02Can you think of any other animals that build structures to help them live more safely?
  3. 03Beavers were hunted nearly to extinction and then brought back by conservationists. Why do you think bringing back a species matters for the rest of the animals in the same area?
  4. 04An underwater entrance to a home is a clever design. Can you think of any buildings that humans have designed with hidden or difficult-to-find entrances?
Try this

Classroom activity

In small groups, try to build a mini 'beaver dam' in a plastic tray of water using only sticks, small stones and modelling clay. Test whether your dam holds back water. Discuss what you would change if you built it again.